Levels of cesium, mercury and lead in fish, and cesium in pond sediments in an inhabited region of the Ukraine near Chernobyl

Samples of crucian carp (Carassius carassius) and sediments collected from 14 ponds within and outside the 30 km exclusion zone southeast of Chernobyl were analyzed for radiocesium; major anions and cations in water were determined for each pond, and other atmospherically- transported pollutants (Pb and Hg) were measured in fish muscle. Up to 20 sediment samples were collected from each pond. Median sediment radiocesium was ≤ 1 Bq g−1 dry mass in all ponds, but some samples contained up to 11 Bq g−1 dry mass. The distribution of radiocesium was very patchy, and could vary over 100% in samples collected a few meters apart. Fish muscle radiocesium ranged from below detection up to 8.2 Bq g−1 dry mass and varied significantly among ponds. All Carassius muscle analyzed contained detectable Hg (0.03 to 1.28 μg g−1 dry mass), and most contained detectable Pb (up to 1.76 μg g−1 dry mass). Water chemistry was a poor predictor of fish contaminant burden, possibly due to the extreme patchiness of the contaminant distribution. Fish size was correlated with muscle Cs content in some ponds, and negatively correlated with muscle Pb concentration. The distributions of radioactive and non-radioactive contaminants were not significantly correlated.